<p>Sandstone-type uranium deposit (STUD) with upper and lower aquiclude is typically mined using in situ leaching (ISL). However, ISL becomes unfeasible when natural aquicludes are absent, leading to leachate migration and groundwater contamination. In this study, microbially induced calcium carbonate precipitation (MICP) technology was employed to construct an artificial aquiclude by reducing the permeability of surrounding sandstone. Simulated sandstone samples were prepared based on the geological characteristics of a STUD in Xinjiang, China, and a series of controlled injection experiments were conducted to evaluate the effects of cementation solution concentration, injection flow rate, and number of injection rounds. The permeability evolution and calcium carbonate distribution were quantified. X-ray diffraction and computed tomography scanning were used to reveal the pore-scale changes. The results show that increasing cementation concentration and injection rounds significantly reduced permeability. A gradual increase in flow rate and concentration led to more uniform CaCO₃ distribution and minimized spatial variation in permeability. High cementation solution concentration increased the size of calcium carbonate crystals. Microstructural analysis confirmed reduced porosity and pore connectivity after MICP treatment. The effective permeability calculated using a ball-and-stick model aligned with the experimental data. This study demonstrates that MICP is a promising technique for artificial aquiclude formation in STUDs, providing both macroscale effectiveness and microstructural insight.</p>